Needleless access devices allow a healthcare professional to, e.g., replace/add IV bags, and/or access an IV line without having to use a needle. FIG. 1 is a cut-away view of a current needleless access device 100. Needleless access device 100 includes female luer fitting 101, male luer fitting 102, and valve 103. When in use, male luer fitting 102 is connected to, e.g., a catheter or to a female luer, and female luer fitting 101 is connected to a fluid reservoir. Female luer fitting 101 is connected to the fluid reservoir via a second male luer fitting (not shown) that includes a hollow member inserted through the top of female luer fitting 101, collapsing valve 103 down into volume 104 to break the seal and create a fluid flow path. The hollow member of the second male luer fitting delivers the fluid, which flows around valve 103 into channels (not shown) in male luer fitting 102 and into the catheter or female luer.
Inside valve 103 is a gap (or septum, not shown), that is filled with air. Device 100 is a positive displacement device, so that when a new connection is made at female luer fitting 101, device 100 pulls fluid in from the male side of the valve (i.e., the side proximate male luer fitting 102). When a disconnection is made at female luer fitting 101, device 100 pushes fluid in from the female side (i.e., the side proximate the top of female luer fitting 101. The advantage of positive displacement is that when a disconnection is made, device 100 expels fluid out of the male luer fitting 102 and effectively flushing the catheter. By contrast, many devices on the market today have negative displacement, so that when a syringe is disconnected, such device pulls a little bit of fluid from the male luer side, which, if a catheter is being used, means that blood is pulled into the catheter lumen. Blood that is left in a catheter lumen may clot and cause health problems for the patient.
An additional feature of device 100 is that when the female end is accessed by a male luer (not shown), valve 103 is elastic so that it can bend out of the way to allow flow and then return to its original shape after a disconnection is made at the female end. Thus, device 100 re-seals itself and forms a flat surface that can be disinfected at the top surface 110 using an alcohol swab. By contrast, many devices on the market use plastic valves that cannot flex to move out of the way to allow flow, thus requiring the use of valves that are slanted or incorporating features at the top, making swabbing difficult.
Device 100 has a symmetrical valve body providing symmetrical wall strength, as well as weakness points on both sides by virtue of duckbills 105. Furthermore, device 100 includes uniform wall thickness in the valve body, even at and around duckbills 105. The contact area between a luer and the top surface 110 of valve 103 and the type of luer motion will dictate the form of collapse of the valve body. Device 100 provides good performance, but could benefit from enhanced repeatability and controllability of collapse.